3 switches running 1 light revisited

From what I could tell before I disassembled it all, the hot wire came into the box and the black wires from all the other wires were twisted together, one of those black went to the light, another went to the 3way switch, another went to a different switch (porch light) and another went to an outgoing line that I haven't tracked down. One last black wire was pigtailed from the wirenut to the porch light switch. All the white wires were twisted together from all the lines, with one wire going out to the 3way switch. I couldn't say any more clearly than that. I've never seen so much wire packed into such a tight space. I had to start untwisting before I had the full picture in order to be able to disentangle some of the wires.

I'm not worried about putting the porch light switch back together or continuing that other outbound line. As for the 3-way switch and the light, I know I can split that one hot wire and run that up to the light, then proceed to rewire based on the attached diagram. I was just wondering how the last guy got this to work with the light being terminal and the second 3-way also being terminal, and the incoming power seemingly twisted together with the first 3-way and the wire going to the light.

I also didn't understand why my light was permanently on after I merely used the 14/3 wire already in the light box to connect the light with white and black, and left the red wire hanging free. And for that matter, I don't know why a 14/3 wire was run to the light. When the ceiling fan was there, the red wire went to a blue wire on the fan, but with a cheap placeholder light fixture, there is only a place for black and white wires.

I don't even try to understand Egyptian spaghetti like that. (black red white gold). I consider that "making it unnecessarily hard". Life goes easier if you just color code your wires by their function.

Yellow = travelers
Red = switched-hot

Draw a box for lamp and each switch, then draw the cable coming in from supply with black and white wire. Then draw some "cable" between the boxes as they are actually cabled, just draw 2 lines with some space between them and we'll draw in wires later, and we'll color code the wires by function.


From the 3-way, through the 4-way and to the other 3-way, draw TWO YELLOW wires. Two. Yellow are travlers and there are 2.

Draw 1 black wire from supply to either of the switches. Black is always-hot.

Draw 1 white wire from supply to the lamp. Also to the switch that got black because of NEC 2011 Code. White is neutral.

Draw 1 red wire from the *other* 3-way switch to the lamp. Red is switched-hot.


Now, most of the time, you find there are 3 wires in most of these "cables". And everything "just works out".

Often, you can correct things just by rearranging components. For instance putting the 4-way in the wrong place will create a LOT of work and unnecessary wires.

Sometimes, though, your best efforts reach an impasse.

Sometimes you find 4 wires in a cable - often relating to that NEC 2011 neutral we ran to a switch. You can either violate Code at this point and omit it, or use the correct /4 cable. And by "can" I mean you'll get written up by the inspector and have to fix it.

If you find 5 wires in a cable, then it's time for smurf tube and THHN.

When you get to actually installing it, when white is not neutral it MUST be re-marked and must be used for always-hot if that is present. Feel free to use colored electrical tape to re-mark everything else by function. Always mark both ends of a wire the same. It really does make life easier.